Auxiliary propulsion device for ships



Sept. 2, 1969 K. c. B. THORDE N 3,454,330

AUXILIARY PROPULSION DEVICE FOR SHIPS Filed April 11, 1968 2 Sheets-Sheet l FIG.1

Mm, v MM flTroANEYS Sept. 2, 1969 K. G. B. THoRDN 3,464,380

AUXILIARY PROPULSION DEVICE FOR SHIPS Filed April 11, 196,8 2 Sheets-Sheet 2 INVENTOR.

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3,464,380 AUXILIARY PROPULSION DEVICE FOR SHIPS Karl Gustaf Birger Thordn, Marklandsgatan 5, Goteborg, Sweden Filed Apr. 11, 1968, Ser. No. 720,596 Claims priority, application Sweden, Apr. 19, 1967, 5,467/ 67 Int. Cl. 1363b 1/30 U.S. Cl. 115-29 7 Claims ABSTRACT OF THE DISCLOSURE An auxiliary propulsion device for maneuvering ships at low speed comprising a reciprocating rod having an oscillating plate pivotally connected to its end, said plate generating a driving force on the ship due to the flow of water created between said plate and the shell plating of the ship.

Big ships running with low speed have a very bad steering ability due to the small hydrodynamical forces acting on the relatively small surface of the rudder. Below a speed of knots the ship can be considered not to have full steerability. In harbours and when passing narrow passages or bringing a ship to the quayside therefore commonly drag assistance of a tug is required which will involve increased cost of running and in dependence of available strange help. Therefore various ways have been tried for solving the problem of steerability at low speed, and a propeller arranged in a tunnel transversely of the ship at the bow thereof has gained certain use. However, said device only acts on the stem part of the ship so that it will turn about the stern part whereas a displacement athwart the ship only can be carried out with such propeller at both ends of the ship. Such a construction is expensive and complicated and the tunnels will influence the resistance of flow around the hull in an unfavourable manner. Another solution of the problem is a propeller having a vertical shaft but such a device is also expensive and causes greater resistance of flow than a conventional propeller driving mechanism. In tankers the cargo oil pumps possibly may be used in order to perform corrections required for maneuvering of the ship by the reaction force of a water jet.

The present invention is concerned with a simple device by means of which the ship can be steered in an arbitrary direction and in which the device only will require small constructional amendments of the hull and simultaneously the device in inoperative position does not cause any considerable resistance of flow.

The device comprises a plate pivotally connected to a reciprocating rod said plate having its pivot axis substantially at right angles to a symmetry axis of the plate so that said plate when moved by the rod can perform an oscillating movement generating a driving force on the ship, and the characterizing feature is that the pivot axis and the inflow edge of the plate are arranged on the same side of the centre of gravity of the surface of the plate, said centre being located on said symmetry axis, and that a stopper is provided between said pivot axis and said inflow edge, said stopper being joined to the plate and to a part connected to the ship, respectively, said stopper only permitting a limited oscillating movement of the plate, the length of the plate between the pivot axis and the inflow edge being so fitted that said edge abuts the shell plating of the ship in the outer dead centre of movement of the rod and the stopper is in blocking position.

One embodiment of the invention will be described with reference to the accompanying drawings in which FIGURE 1 is a schematic sectional view of an auxiliary tent 0 3,464,380 Patented Sept. 2, 1969 propulsion device, FIGURE 2 is a sectional view along the line 11-11 in FIGURE 1 and FIGURES 3a-3e schematically show the device in various operation positions.

In the shell plating 1 of a ship and preferably at the middle part in the longitudinal and transversal direction thereof a case 2 is recessed which case is provided with an opening through the shell plating. Built into the case 2 is an operating device for elfecting a reciprocating movement of a rod 3 which operating device in the embodiment shown consists of a piston 5 movable in a cylinder 4 by alternately conveying a pressure medium into the cylinder on both sides of the piston 5 so that said piston is pressed up and down. The piston 5 is connected to the rod 3 which is guided in a bearing 6 in the case 2. At the free end of the rod 3 a transverse pivot 7 is provided which carries a pair of lugs 9 fastened to a plate 8 located outside the shell plating 1 said plate 8 being swingable on the pivot 7. The rod 3 is provided with longitudinal splines 10 which are guided in corresponding grooves 11 in the inner surface of a sleeve 12 fastened to a gear 13 in mesh with a pinion 14 on a shaft 15 connected to a source of power. An articulated stopper 16 is provided between the gear 13 and the plate 8 which stopper consists of a cylinder 17 connected to the gear 13 and a piston rod 18 in said cylinder connected to the plate 8 said piston rod having a limited length of movement,

The plate 8 is square-shaped, round or may be of some other form having at least one symmetry axis which is directed at right angles to the pivot 7. The centre of gravity TP of the surface of the plate 8 and the connecting point of the rod 3 at the plate 8 are located on said symmetry axis with the connecting point at a distance from the centre of gravity TP whereas the fastening point of the stopper 16 at the plate 8 is located on the same sideas but in a greater distance from the centre of gravity.

The operation of the device will be described with reference to FIGURES 3a-3e. In inoperative position the plate 8 lies close to the shell plating 1 thereby causing a negligible resistance of flow. When the rod 3 is pressed downwards the hydrodynamical forces will act on the plate 8 so that its right edge (inflow edge) as seen in the figures will be turned down whereas the left edge will be kept close to the shell plating as viewed in FIGURE 3b. Thereby the water flows into the more and more widened wedge-formed space between the plate 8 and the shell plating 1. Said movement of the plate 8 will proceed until the stopper 16 will stop the downwardly directed movement of the inflow edge of the plate 8 and then a further downwardly directed movement of the rod 3 and thus of the plate 8 causes a rotating movement on the pivot 7 as shown in FIGURES 3c and 3d. This rotating movement will proceed until the inflow edge of the plate 8 abuts the shell plating 1. During the rotating movement of the plate 8 a flow of water is generated from the wedge-formed space between the plate 8 and the shell plating 1. Said flow of water will go on even when the direction of movement of the rod 3 is reversed for pulling the plate 8 upwards as seen in FIGURE 36 so that the plate 8 finally occupies its initial position. Then a new cycle of operation can begin.

According to the above described scheme of movement of the plate 8 a propulsion force will be generated which is directed to the right in the figures and the ship therefore will move in said direction.

By turning the gear 13 by means of the pinion 14 the plate 8 can be directed in any desired angle to the longitudinal direction of the ship and as the propulsion force always acts at right angles to the pivot axis of the plate 8 the ship can be displaced in any direction desired and thus ahead, astern and in any transverse direction.

In order to generate the movements of the plate 8 as above described the operating device can be modified in various manners. There is only a primary demand that the rod 3 performs a reciprocating movement between two definite dead centres and thereby also a geared crank mechanism can be used. For instance the source of power can be an electromotor, an internal combustion engine, a hydraulic motor or a steam engine and also other sources of power may be conceivable. The efiiciency and the cost of operation are of a relatively secondary importance as the auxiliary propulsion device is in operation only during short periods.

The plate 8 is shown plane but it also can be of single curved or double curved form and along the side edges guide-bars can be provide for preventing flow of water from one side of the plate to the other.

Besides the various parts of the auxiliary propulsion device can be constructed in other ways than shown and described. Thus the stopper 16 can be a rod with a catch said rod being connected to the plate 8 and said catch co-operating with a corresponding catch provided on the rotatable sleeve and the stopper can also consist of a spring or the like co-operating with a firm stop. The propulsion device will operate in the described manner even without a stopping device but the movement of the plate 8 is controlled more accurately by said stopping device.

What I claim is:

1. An auxiliary propulsion device for ships intended for maneuvring at low speed and comprising a reciprocating rod and a plate pivotally connected to said rod, said plate having its pivot axis substantially at right angles to a symmetry axis of the plate so that the plate when moved by the rod is performing an oscillating movement thereby generating a driving force on the ship, characterized in that the pivot and the inflow edge of the plate are arranged on the same side of the centre of gravity of the surface of the plate, said centre being located on said, symmetry axis, stopper means being provided between said pivot and said inflow edge, said stopper means being articulated to theplate and to a part connected to the ship, respectively, for permitting a limited oscillating movement of the plate, the length of the plate between the pivot and the inflow edge being such that said edge abuts the shell plating of the ship in the outer dead centre of movement of the rod and the stopper means is in blocking position.

2. A propulsion device as claimed in claim 1, characterized in turning means for adjusting the pivot in various angles to the longitudinal direction of the ship.

3. A propulsion device as claimed in claim 1, characterized in that a source of power for driving said rod is a reciprocating motor.

4. A propulsion device as claimed in claim 1, characterized in that the source of power for driving the rod is a rotary motor connected to a crank gear.

5. A propulsion device as claimed in claim 2, characterized in that said turning means comprises a rotatable sleeve provided with axial splines co-operating with grooves in said rod, said sleeve having adjusting means for setting the angle of adjustment of the plate.

6. A propulsion device as claimed in claim 1, characterized in that the plate is plane, single curved of double curved.

7. A propulsion device as claimed in claim 1, characterized in that guide-bars are provided along the side edges of the plate for preventing flow of water from one side of the plate to the other.

4/ 1961 Birdsall 115--29 3/1967 Kerandraon ll5-31 XR ANDREW H. FARRELL, Primary Examiner US. Cl. X.R. -'221; l03-80 

